A system used between friends which simply allows someone who brought his/her own beer to a party, but has innocently consumed more than said person's normal maximum limit, to dip into his/her friends stash in order to keep the party rolling.

As with any such plan, there are rules:
1) Do not exercise the overdraught option if you showed up disturbingly understocked.
2) Overdraughting begins with the worst offered beer, then graduates upward based on the stock remaining and tolerance of the original suppliers.
3) Do not make this mistake again with the same amount of beer or you will obtain Mooch status and overdraught protection will be revoked for 1 calendar year.

"Hey Jorte, I notice that you are digging through the fridge for your 8th Dogfish Head 90 Minute IPA, yet I see you only brought a 6 pack of Natural Light. WTF? Your breaking rules 1 and 2 of the OverDraught Protection plan brother!! "